Ventilation Around ring main circuit

[Damian30]

Hi,

I'm running some cables to extend a ring main into my conservatory. I have an electrician coming in a few weeks to check things out and connect up the ring and sockets. I'm provisionally fitting all the cables but leaving everything accessible just in case.

I originally put the cables in the cavity but with the insulation in there, the advise I got on here was that the circuit would need to be down rated, etc.

I've now taken the cables out of the cavity and was going to lay them along the rail which runs along the timber batons supporting the boarded wall. As these cables are within 150mm of the top of the 'wall' I thought this would okay as per the Regs. My only concern is that the cables are pretty much surrounded by the timber rail, plasterboard wall, windowboard, ply board supporting the windowboard, etc. There is a bit of a gap in this channel where air can escape down behind the stud wall but just wanted to check whether there are any problems with this solution.

I'd be very grateful of any views. The attached picture isn't that great but may help explain what I've tried to describe.

Many thanks,

Damian

Untitled

• Damian30
• 24 Nov 2014
• 1

 

[GNServices]

You should really check with the electrician who would pass it as different electricians could have different views on things even though the regs are the same.

 

[EFLImpudence]

The within 150mm of the top of the wall refers to the join with the ceiling - not a top of a wall.

Having said that, I am having trouble orienting your picture.
I cannot see what it is.



Also, being in contact with a material is better for the cable than a small air gap.

 

[Monkeh]

Having said that, I am having trouble orienting your picture.
I cannot see what it is.

It would appear to be the right way up. There's the bottom of a window at the top, windowboard, and a piece of plasterboard on the front.

 

[EFLImpudence]

It would appear to be the right way up. There's the bottom of a window at the top, windowboard, and a piece of plasterboard on the front.

Ah, right.

Well, in that case it will not be in a 'safe zone' there being no accessories in line with the cable.

 

[JohnW2]

The within 150mm of the top of the wall refers to the join with the ceiling - not a top of a wall.

Well, in that case it will not be in a 'safe zone' there being no accessories in line with the cable.

Interesting one this

Although I've never thought about it before (and therefore would probably have given the same answers as you) when one looks at the regs, and despite what you say, 522.6.101(v) says nothing about 'the join with the ceiling' - but does, indeed, talk only of "within 150mm of the top of the wall or partition" !!

I suppose we now get a debate about what the person who wrote that actually 'intended'!

Kind Regards, John

 

[sparkwright]

I don't think installing cables like that was ever 'intended' when the zones were written.

Think I would have prefered the cables in the cavity!

Still, I suppose you can argue rules are open to interpretation.

I suppose it's a bit late to change it now.

 

[JohnW2]

I don't think installing cables like that was ever 'intended' when the zones were written.

I, too, doubt that was the intention of the author (few few would suspect that a 'reg-compliant' cable would be hidden at the top of a 'dwarf wall') - but, to someone who wants to work to the strict word of the regs, those words could appear to be fairly clear!

Kind Regards, John

 

[Damian30]

Hi,

I took the guidance literally and thought it is at the top of a wall and is 'protected by the laminated windowboard (i.e. no one is going to drill/nail through it).

It would be a real pain moving it down the wall and in line with the sockets as timber batons have been used and I'll need to remove the board and drill through them all. I fitted the boards when thinking the cable in the cavity was okay.

I'm having a bit of a nightmare here, got to get the conservatory finished asap as I've been working on it for 2 years now!

Thanks for the replies,

Damian

 

[EFLImpudence]

Can't argue with the logic.

Could be handy for running cables to outbuildings.

 

[JohnW2]

Can't argue with the logic. ... Could be handy for running cables to outbuildings.

True - but, IMO, potentially hazardous. As I said, not many people are going to think of that as a safe zone, and it is, for example, just about the right place for the top screws of the brackets for an under-window radiator!

Kind Regards, John

 

[Damian30]

Thanks for replies.

Obviously kicking myself after spending hours removing the cable from the cavity and having to refit the plywood boards bringing the cavity nice and level.

Any ideas what I could do, apart from removing plasterbiard and fitting horizontal with the sockets. Wondered whether I could replace the wooden 20mm x 20mm rails with something metallic as a protective conduit? It has to go around several angled bends so farthing it could be interesting.

Solutions appreciated as I'm losing the will to carry on with this.

Many thanks,

Damian

 

[JohnW2]

Any ideas what I could do, apart from removing plasterbiard and fitting horizontal with the sockets. Wondered whether I could replace the wooden 20mm x 20mm rails with something metallic as a protective conduit? It has to go around several angled bends so farthing it could be interesting. ... Solutions appreciated as I'm losing the will to carry on with this.

How deep can you get the cable relative to the room-side of the boarding? If it were at least 50mm below the wall surface, it wouldn't have to be in a safe zone.

Kind Regards, John

 

[Damian30]

The timber batons are 30mm thick (although at spaced off the wall in places as it is not straight) with 10mm board. I could drop the cable behind the rails so will have a little more protection but still within 50mm of the front of the board and under the windowboard.

 

[mikeyd]

Hi,

Hello.

I'd be very grateful of any views. The attached picture isn't that great but may help explain what I've tried to describe

Yep. Picture isn't much use.

There must be a reason why you haven't run the cables normally. It would help if you could take the time to say why you have decided to route the cable as you have shown.

I can't see it from here, but why didn't you run a horizontal cable at socket level all the way around the room with a socket on every wall?